Genetic Mutation of Hb E/beta Thalassemia Patient in Bangladesh and Its Relation With Clinical Severity

Abstract

Background: Hemoglobin E/β-thalassemia is a common inherited hemoglobin disorder among South Asian countries. The phenotypically diverse presentation of the disease is often attributed to coinheritance of β-globin (HBB) gene mutations. The current study described the phenotype and genetic basis of Hb E/β-thalassemia patients and assessed its relation with clinical severity.Methods: A total of 32 patients were included in this cross-sectional study. Cases were confirmed by using capillary hemoglobin electrophoresis or high-performance liquid chromatography. Those with positive findings were further analyzed with clinical information and ancestral data either from the interview or medical records. Data collection was confined to May 2019 and July 2020. Gene sequencing was performed using Sanger’s sequencing method for mutational analysis, and Mahidol scoring was used to grade clinical severity.Result: A total of 13 heterozygous mutations were identified in the HBB gene. Of all, IVS-1-5 (G>C) (n=17, 53.1%) was the most common, and codon 30 (G>C) (n=4, 12.5%) was the second most common mutations. According to the Mahidol scoring system, 37.5% (n=12) were classified as phenotypically mild, 43.8% (n=14) as moderate and 18.8% (n=6) as severe. The IVS-1-5(G>C) mutation was found to be frequently associated with severe disease and showed no mild form.Conclusion: The present study described the clinical severity and its association with genetic mutations in hemoglobin E/β-thalassemia patients. This finding could guide individually tailored management strategies for this particular group of patients.